Extension attachment for ladders, scaffolds and the like



w. 1.. HOBBS maze, ma.

EXTENSION ATTACHMENT FOR LADDERS, SGAFFOLDS AND THE LIKE Filed June 5, 1936 ATTORNEY Patented Oct. 20, 1936 UNITED STATES PATENT OFFEE EXTENSION ATTACHIWENT FOR LADDERS, SCAFFOLDS AND THE LIKE William L. Hobbs, Oklahoma City, Okla.

Application June 5, 1936, Serial No. 83,655

6 Claims. (Cl. 228-63) My invention relates to ladder attachments for advantages thereof; and it is also understood that use in adding an extension to a ladder and more the drawing is to be interpreted as being sparticularly to a lengthwise adjustable attachtrative and not restrictive. ment of this type. The inventive idea involved is capable of re- The objects of the invention are to provide a ceiving a variety of mechanical expressions one device of this class which will enable an operator of which, for the purpose of illustrating the in to set a ladder in a vertical position against the Vention, is shown in the accompanying drawing side of a house or against an inside wall regard- Wherein: less of the uneven base on which its two legs rest; The device comprises a pair of interlocking which will allow a ladder or scaffold to have each members I and 2, made of any suitable material, 10 of its supporting members rest on a base which one side of each member having a series of doveis on a different level than that on which its tail joints cut therein, as designated by the nu- Other leg or legs rest; which may in addition to meral 3, for co-operating with the identically its use in connection with an ordinary straight sized joints of the other member to lock the two 10 ladder or scaffold, be used on saw horses, step members together in various longitudinal posiladders and the like; which will prevent the tions. It will be noticed that the joints extend necessity of an operator carrying a specific size from the ends 4 and 5 of each of the members of extension for each specific job and for each I and 2 to a point past their centers, but do not individual ladder or scaffold, by making it posextend to the opposite ends 6 and I. The ends sible for him to use any piece of wood which 6 and 1 are formed at right angles to the mem- 20 may be handy, for his extension piece; which does hers I and 2, and serve as supports, as clearly not weaken the ladder or scaffold with which it shown in Figs. 1 and 2. Adjacent the outer ends is used; which provides a factor of safety not 6 and 1, each member has an offset bend, desigprovided heretofore on ladder extensions; which nated by numerals 8 and 9, to center the respecis compact and easy for a workman to carry in tive ends 6 and l, and to cause the weight placed 25 his tool kit; which may be used to fasten two on the supports to be distributed along the center ladders together; and, which will be eificient in line of the assembled device.

accomplishing all the purposes for which it is Joint clamps I0 and Il are provided, one on intended. each of the members I and 2. They are pivoted With these and other objects in view as on rivets I2 and I3 respectively, and are curved, 30 will more fully appear hereinbelow, my invention as at I4 so that the chain eyelets I5 and I6 will consists in the construction, novel features, and not interfere with their pivotal movement. combination of parts hereinafter more fully de- These clamps serve only as an additional safety scribed, pointed out in the claims hereto apmeasure to prevent the members I and 2 from pended, and illustrated in the accompanying slipping sidewise and disengaging from each other. 35

one-sheet drawing, of which, I prefer to use them, but they are not a necessity Figure l is a perspective view of a pair of the for the proper operation of the device. devices installed on a stepladder; The chain eyelets I5 and I 6 serve to keep the Fig.2 is a front view showing one of the devices individual chains I1 and I8 attached to the deinstalled on one leg of a straight ladder, the ladder vice so that they will be handy at all times. The 40 being only fragmentarily shown; chains are equipped with small hooks I9 and 20 Fig. 3 is a perspective view of the device cornto facilitate fastening them around the ladder plete, showing the various parts more in detail; and extension piece. The eyelets, of course, are

and, not necessary to the eflicient operation or use of Fig. 4 is a fragmentary view of the end of one the device, and may be eliminated if desired. 45 of the twin interlocking elements, showing its In operation, any pair of boards 2| and 22 dovetail construction. may be chosen by the operator, for use as ex- Like characters of reference designate like parts tension pieces. If they are not of the same length, in all the figures. the two devices used may be adjusted to suit It is understood that various changes in the their difference in length, as well as to suit the 50 form, proportion, size, shape, weight, material difference in level of the bases on which the and other details of construction, within the extension pieces are to rest. After the proper scope of my invention may be resorted to without adjustment in length has been made the two departing from the spirit or broad principle of members I and 2 are interlocked by means of the my invention and without sacrificing any of the dovetail joints 3, thus forming a complete unit, 55

which is placed fiat against the outside of the leg of the ladder, as shown in Figs. 1 and 2, with the lower end of the ladder leg seated on one end 7 of the device. The extension piece 22 is then placed fiat against the outside surface of the device, substantially parallel to the ladder leg, and its upper end is seated on the lower surface of the end 6. Since the clamps l0 and H, and the eyelets l5 and I6 are of thin material, they allow both the ladder leg and the extension piece to fit snugly against the flat sides of the device. The chains I! and I8 are now tightly wound about the extension piece, my unitary device, and the ladder leg, and secured tightly in position by fastening the hooks l9 and 20 into adjacent links of the chains. These chains prevent any side play between the extension piece and ladder leg, and the opposite ends 6 and 1 of my device prevent any possible end play or relative longitudinal movement between the two.

Fig. 1 shows two of the devices in use on the two step supporting legs of a step ladder when its two pairs of legs are resting on diiferent stair steps. I call attention that the two devices might be attached, one to one of the step supporting legs and one to one of the other legsthus making it possible to have the top step of the ladder in a position at right angles to its position as shown in Fig. 1.

Fig. 2 shows one of the devices similarly attached to one leg of an ordinary straight ladder. It will be noted that the rungs of the ladder are not used in connection with the device, and it may thus be used equally well on a scafiold, or on any object on which an extension is needed.

While I have described and illustrated a preferred embodiment of the invention I am aware that numerous alterations and changes may be made therein, and I do not wish to be limited except by the prior art and the scope of the appended claims.

I claim:

1. An extension attachment of the class described comprising two complemental identical main body members having a series of dovetail joints in one side and an end formed at right angles to the main body portion so that when in assembled and locked relation the end portions extend at right angles in opposite directions from member, formed on the opposite ends of the two members and extending substantially at right angles to the main body members; and a pair of clamps, one pivoted on each member and each adapted to fit along the opposite sides of the interlocked body members and aid in maintaining the interlocked relation.

3. A lengthwise adjustable extension. device comprising two main body members each having a straight edge, an end forming a support bent at right angles to its fiat side, and an irregularly formed edge adapted to fit a complemental irregularly formed edge in the other member, so that whenin locked relation the two support ends are opposite each other, substantially parallel to each other, and extend in opposite directions from the assembled device.

4. An extension attachment of the class described comprising two body members each having a portion of one side edge adapted to complementally fit and securely engage an opposite side portion of the other member, and each member having one end formed at right angles to its main body portion, said right angled portions adapted to fit oppositely to each other when said body members are complementally engaged and positioned, and a pair of clamps one adapted to pivot on each member and each adapted to fit along the opposite sides of said interlocked body members and to aid in maintaining the interlocked relation. 7

5. The combination with two of the main members of a ladder and with two suitable extension pieces adapted to fit said members, of an extension attachment as described comprising two body members each having a portion of one side edge adapted to complementally fit andsecurely engage an opposite side portion of the other member each such body member having one end formed at right angles to its body portion, said right angled portions adapted to fit oppositely adapted to pivot on each member and each adapted to fit along the opposite sides of said interlocked body membersand' to aid in maintaining the interlocked relation.

6. Organization as described in claim 5, and two pairs of chains adapted to holdsaid two main members said extension pieces and said extension attachment insecure interlocking relationship. I

WILLIAM L. HOBBS. 

